Credit

Caption

Mapping the human genome: computer analysis of the DNA sequence of the human HL-A system, a gene cluster located on chromosome 6 in humans. This computer screen at CEPH, St-Louis Hospital, France, represents the DNA sequence graphically. The four organic bases, the variable components of each DNA nucleotide, are shown in different colours: adenine (green), thymine (red), cytosine (blue) and guanine (yellow). The HL-A gene complex, originally identified because of its role in transplant rejection, has been implicated in many aspects of immunology. This research at CEPH is part of the human genome project, a worldwide study of the total collection of human genes.